Trevor Chauvin (left) and Cody Garcia will sing “Agony” from “Into the Woods” as part of “Cabaret for a Cause.” (Darrin Newhardt, center, is serving as music director.) The performance, featuring more than a dozen of the city's musical theater performers, will benefit the Playhouse Conservatory, the theater's education program. It will include a “Broadway Backwards” set, in which the men sing women's roles and vice versa; that will include Beth Erwin singing “I Believe” from “The Book of Mormon” and Don Braswell singing “Shy” from “Once Upon a Mattress.”